1. Field of the Invention
The present invention relates to improvements in air filter housings. More particularly, the invention relates to improvements particularly suited for providing increased air filtration with lower pressure drops for enhanced air filtration with easily replaceable filters. In particular, the present invention relates specifically to an angled filtration module.
2. Description of the Known Art
As will be appreciated by those skilled in the art, air filters and housings are known in various forms. The universal individual air filter holding frame has been around for almost half a century and is still by far the most popular face loaded type filter frame on the market. While different filters may be used in the housing, these types of frames require use of separate clips of different types according to the style of filter used. These clips have to be installed initially and then unclipped and reattached to either lances in the frame or the filter itself each time the filter is changed for proper seating against the back gasket. This is time consuming and troublesome due to the awkward nature of the clips and the quantities involved, typically four clips per frame. These frames are also directly joined together in banks and therefore have very little space between filters and clips which adds to the difficulty. Because they are mounted in a wall arrangement perpendicular to the airflow, the velocity has been limited to typically 500 fpm or less which is the most common upper limit for testing air filters. Any higher velocity would jeopardize the efficiency and structural integrity of the filter if it was not manufactured and tested accordingly. Higher velocities also typically decrease the efficiency of any filter. Velocities beyond this threshold cause an increase in pressure drop, sometime dramatically, creating a requirement for an increase in fan motor horsepower and energy use. As a result, units selected requiring these gasketed face loaded filter frames have overall size and capacity limitations due to many times just the filter velocity only. The other required components in the system could many times be selected for higher velocities such as the coils, heaters, etc. if the filters wire within design parameters.
Patents disclosing information relevant to air filters include:
U.S. Pat. No. 8,747,506, issued to Borkent, et al. on Jun. 10, 2014 entitled Atmospheric air filtration unit, air prefiltration unit, and associated air filtration system for removable attachment thereof; U.S. Pat. No. 8,603,229, issued to Tatarchuk, et al. on Dec. 10, 2013 entitled Multielement structured arrays (MESA's) for cost effective and high efficiency treatment of fluids; U.S. Pat. No. 7,585,346, issued to Roseberry, et al. on Sep. 8, 2009 entitled Media holding module; U.S. Pat. No. 7,156,898, issued to Jaisinghani on Jan. 2, 2007 entitled Low pressure drop deep electrically enhanced filter; U.S. Pat. No. 6,835,128, issued to Olson on Dec. 28, 2004 entitled Ceiling mounted air filtering and distribution apparatus operated independently of any HVAC system; U.S. Pat. No. D469,863, issued to Kice on Feb. 4, 2003 entitled Drop front aspirator, U.S. Pat. No. 1,455,826, issued to Gillingham, et al. on Apr. 16, 2002 entitled Filter Apparatus; U.S. Pat. No. 5,733,350, issued to Muller, et al. on Mar. 31, 1998 entitled Container for solid filtration media and filtration system utilizing same; U.S. Pat. No. 5,593,476, issued to Coppom on Jan. 14, 1997 entitled Method and apparatus for use in electronically enhanced air filtration; U.S. Pat. No. 5,223,011, issued to Hanni on Jun. 29, 1993 entitled Air filter assembly; U.S. Pat. No. 4,969,936, issued to Schweigert, et al. on Nov. 13, 1990 entitled Filtration apparatus; U.S. Pat. No. 4,685,944, issued to Allan, et al. on Aug. 11, 1987 entitled High efficiency particulate air filter; and U.S. Pat. No. 2,966,959, issued to Max Neumann Gerhard, on Jan. 3, 1961 entitled V shaped filter cell housing and means of sealing filter frames therein. Each of these patents is hereby expressly incorporated by reference in each of their entirety.
From these prior references it may be seen that these prior art patents are very limited in their teaching and utilization, and an improved modular air filter is needed to overcome these limitations.